Preparation of Highly Dispersed Ni Catalysts for H 2 Production for Polymer Electrolyte Fuel Cells

Reforming of methane and propane with supported Ni catalysts was investigated for the production of hydrogen for polymer electrolyte fuel cells (PEFCs). Supported Ni catalysts were prepared from Mg(Ni)-Al hydrotalicite-like compounds (HTlcs) as the precursor. The precursors were prepared by the co-precipitation method from nitrates of the metal components, thermally decomposed, and then in-situ reduced to form supported Ni catalysts. Ni2+ can effectively replace the Mg2+ site in the HTlcs, resulting in the formation of highly dispersed and stable Ni metal particles on supported Ni catalysts. Supported Ni catalysts prepared by this method showed higher activity than catalysts prepared by the conventional impregnation method such as Ni/alpha-Al2O3 and Ni/MgO. Moreover, the activity and stability of supported Ni catalysts were improved by combining a small amount of noble metals by adopting the "memory effect," which allows the reconstitution of the original hydrotalcite-like structure, and were effective for the production of hydrogen under the daily start-up and shutd-own operations.